In the related art, a waterproof connector that connects wires is mounted in an automobile or the like. For example, there has been known a connector that includes a female connector having a cylindrical inner housing in which a cavity that is able to accommodate a female terminal is formed and a cylindrical outer housing that surrounds the inner housing, and a male connector having a cylindrical male housing in which a cavity that is able to accommodate a male terminal is formed, the connector is formed by fitting both connectors together.
This type of connecter has an annular rubber packing mounted on an outer circumferential surface of the inner housing of the female connector. When both connectors are fitted to each other, the male housing is inserted into a gap between the inner housing and the outer housing of the female connector and packing come into close contact with the outer circumferential surface of the inner housing and the inner circumferential surface of the male housing, respectively. In this manner, water is prevented from infiltrating into the gap between cavities.
Incidentally, this type of connector includes locking mechanism for maintaining a fitting state of the male and female connectors. For example, an elastic member formed in the male housing is elastically inserted and locked into a locking hole formed in the outer housing of the female connector, and thereby both housings are locked to each other. However, when the male housing is inserted into the female housing in shaky fitting, there is a concern that the male housing will be locked in a state of shifting from a normal position, as a result, part of the packing will be intensely pressed and crushed, and then it is not possible to secure sealability.
In comparison, as a waterproof structure in which packing is not used, for example, there has been known a structure in which a resin sealing plate having elasticity is provided on a deep inside surface of the female housing, the cylindrical distal end of the male housing abuts against an annular sealing plate of the female housing over the entire circumference, and thereby infiltration of water is prevented when both connectors fit to each other (for example, refer to Patent Document 1).